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Topic: Loud, scratchy volume pot... |
Jon Nygren
From:
Wisconsin, USA
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Posted 7 Feb 2011 8:07 pm |
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So i'm getting a loud scratching, popping noise when I turn down the guitar volume, and it's plugged into one channel of a two channel amp(amp is an old standel hybrid). The other channel is fine, and I dont get any scratchiness when I turn the amps volume pots.
Could this be an input jack problem? |
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Jack Stoner
From:
Kansas City, MO
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Posted 8 Feb 2011 3:06 am
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| It's the pot (volume control). Sometimes spraying the pot with volume control cleaner (not contact cleaner) will fix it. In other cases it will require replacing the pot with a new one. |
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Jon Nygren
From:
Wisconsin, USA
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Posted 8 Feb 2011 5:59 am
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This is why I dont think it's a pot- it doesnt do this when i'm plugged into other channel....I can turn the guitar volume up and down, and I get no noise. It's just one channel(this amp has two channels, volume/contour and treble/bass each). And it doesnt really sound much like a dirty pot- it really sounds like DC across my guitar volume pot?
I'm hoping theres not a cap going bad in the SS module on that channel, but that could be. |
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Ken Fox
From:
Nashville GA USA
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Posted 8 Feb 2011 6:01 am
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| Put in a guitar cable to the faulty channel's input jack and measure from tip to sleeve for DC voltage. If any is presnet that will cause the scratchy sound. |
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Lee Baucum
From:
McAllen, Texas (Extreme South) The Final Frontier
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Posted 8 Feb 2011 6:05 am
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This happens with my 1985 Evans FET-500LV. Using a passive volume pedal I get a scratchy noise with Input 1. No noise using Input 2.
This is true with both of my Goodrich volume pedals. Both have new pots purchased from Tom Bradshaw.
No scratchy sounds with any other amps. |
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Jon Nygren
From:
Wisconsin, USA
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Posted 8 Feb 2011 7:00 am
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| Ken Fox wrote: |
| Put in a guitar cable to the faulty channel's input jack and measure from tip to sleeve for DC voltage. If any is presnet that will cause the scratchy sound. |
Thanks Ken, I will try that tonight. I'm pretty sure i'll find DC there.
I looked at the green module schem at standel's website...no idea if this is similar to the one in my amp (early '63 72J15) but it has a .47 capacitor, connected directly to the input. Might try a fresh cap inline with this to see if it solves the problem. If it does, I may have to build me a new module.
While i'm at it, I need to change the filters and put in a grounded cord...not one part has been changed on this amp since it left the factory, dead stock! I'm getting a slight ghost note when I hit a low F#, i'm guessing the filters are dying.
It actually sounds pretty good considering it need maintenance. |
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